1. Field of the Invention
The present invention relates to a grip for a golf club shaft, and more particularly, to an improvement of a double-layered tubular grip for a golf club shaft.
2. Description of the Related Art
Many kinds of tubular grips for golf club shafts have been known; a typical of one such grip being a single-layered vulcanized rubber grip made of one piece of non-porous, vulcanized rubber. Such a single-layered vulcanized rubber grip has a relatively heavy weight, for example, 45 to 50 g is usual, and thus has a drawback in that, when the grip is mounted on a golf club shaft, the weight of the golf club is increased, and accordingly, it becomes difficult to increase the speed of a head of the golf club during a swing motion thereof.
A single-layered foam rubber grip also has been used. The single-layered foam rubber grip has a relatively light weight, for example, 25 to 30 g is usual, due to the porous structure thereof, and thus can eliminate the above-mentioned drawback. Nevertheless, the single-layered foam rubber grip has a drawback in that the surface thereof having, usually, a plurality of grooves is easily worn by long term use, and thus a player's hands easily slip on the grip.
Japanese Unexamined Utility Model Publication No. 53-12061 discloses a double-layered tubular grip for a golf club shaft. Such a known double-layered tubular grip comprises an inner layer made of a porous material having a rubber-like elasticity, and a non-porous outer layer made of a vulcanized rubber. This known double-layered tubular grip has a weight less than that of the above-mentioned single-layered vulcanized rubber grip, and the wear of the surface of the grip is reduced due to the existence of non-porous outer layer. In this known double-layered tubular grip, however, the outer layer is undetachably secured to the inner layer, and thus it is impossible to change only the outer layer while leaving the inner layer on the golf club shaft.
This raises a problem in that, although the wear on the surface of the grip is reduced, nevertheless, after a long period of use, the grip surface becomes slippery, and thus should be changed. However, as mentioned above, it is impossible to change only the outer grip layer.